Set in futuristic Metro City, Astro Boy is about a young robot with incredible powers created by a brilliant scientist in the image of the son he has lost. Unable to fulfill the grieving man's expectations, our hero embarks on a journey in search of acceptance, experiencing betrayal and a netherworld of robot gladiators, before he returns to save Metro City and reconcile with the father who had rejected him.

In 2925 A.D., the scientists of Metro City decide to rescue their city from the earth's pollution by removing it from Earth. The city is a floating metropolis that hovers above the planet's surface, its population tended to by a robotic workforce. The student Toby Tenma goes to visit his workaholic father Dr. Tenma, head of the Ministry of Science, arriving just as Tenma is meeting with the militaristic President Stone. They view a lecture held by Doctor Elefun on a new energy source extracted from the heart of a star, a self-sustaining positive Blue Core energy that could repair the world's pollution, yet it has a negative Red Core byproduct. Stone is intent on using the red core to fuel his new "Peacekeeper" military robot, bu after putting it in, the robot rampages, and it vaporizes Toby before Doctor Elefun is able to shut it down.
http://www.imdb.com/title/tt0375568/